On Sat, 23 Nov 2013 11:41:40 -0600, Nightcrawler® wrote:

The transformer is obviously dead. Replace it immediately. This
will at least let you know if the system will work with the transformer
functional. Step two would be to figure out what is wrong with
the battery back-up. Have you checked for fuses, yet?

I don't see a fuse on the Radionics D2212 BLT circuit board:
http://farm3.staticflickr.com/2866/1...cdea2144_o.gif

And, I don't (yet) see a fuse in the Radionics D2212B LT diagram:
http://farm3.staticflickr.com/2861/1...69e24a57_o.gif

And, I don't see an inline fuse in the "rats nest" below the board:
http://farm8.staticflickr.com/7409/1...0ebeea29_o.gif

http://www.alarmhow.net/manuals/Radi...n%20Manual.pdf

On Sat, 23 Nov 2013 16:39:07 -0600, Nightcrawler® wrote:

http://www.alarmhow.net/manuals/Radi...n%20Manual.pdf

That's a very nice find, especially since three things appear to have been blown
when I turned the power off without turning off the generator:

1. The ELK TRG140 16.5V AC transformer secondary windings are now open
2. The D135A battery-protection board cap is apparently blown
3. The Radionics D2212B alarm circuit board is apparently malfunctioning

The test of the Radionics board was to hook the battery directly to
the power and ground leads. That drew 98ma and the alarm system merely
beeped an incessant single beeeeeeeeeeeeeeep for the entire time that
I left the battery connected.

http://farm8.staticflickr.com/7370/1...4f8a7d31_o.gif

"Danny D'Amico" wrote in message
...
On Sat, 23 Nov 2013 11:41:40 -0600, Nightcrawler® wrote:

The transformer is obviously dead. Replace it immediately. This
will at least let you know if the system will work with the transformer
functional. Step two would be to figure out what is wrong with
the battery back-up. Have you checked for fuses, yet?

I don't see a fuse on the Radionics D2212 BLT circuit board:
http://farm3.staticflickr.com/2866/1...cdea2144_o.gif

And, I don't (yet) see a fuse in the Radionics D2212B LT diagram:
http://farm3.staticflickr.com/2861/1...69e24a57_o.gif

And, I don't see an inline fuse in the "rats nest" below the board:
http://farm8.staticflickr.com/7409/1...0ebeea29_o.gif


The bottom three terminals with the Green, Red, and red and black wires are
the power to your external panels. Normally, the green is a data line, the
black should be a negative 12 volt line and the red should be +12 volts. If
someone mixed up that wiring, it could present a short circuit to the power
supply and battery. You might want to go through all the mess and clean it
up. A fault there could also explain the transformer failure.

On Tue, 26 Nov 2013 01:33:21 -0500, tm wrote:

If someone mixed up that wiring, it could present a short circuit
to the power supply and battery.

The alarm has been working for years, so, I'm pretty sure the wires
didn't all of a sudden get changed.

The good news is that the new transformer arrived today.

However, the voltage output wasn't at all what I had expected from a
16.5VAC transformer secondary.
http://farm6.staticflickr.com/5532/1...7612e531_o.gif

I measured:
a) 20 VAC across the secondary
b) 3.54 VAC across on side of the secondary to ground
c) 0.98VAC across the other side of the secondary to ground

Huh?

"Danny D'Amico" wrote in message
news
On Tue, 26 Nov 2013 01:33:21 -0500, tm wrote:

If someone mixed up that wiring, it could present a short circuit
to the power supply and battery.

The alarm has been working for years, so, I'm pretty sure the wires
didn't all of a sudden get changed.

The good news is that the new transformer arrived today.

However, the voltage output wasn't at all what I had expected from a
16.5VAC transformer secondary.
http://farm6.staticflickr.com/5532/1...7612e531_o.gif

I measured:
a) 20 VAC across the secondary
b) 3.54 VAC across on side of the secondary to ground
c) 0.98VAC across the other side of the secondary to ground

Huh?


That's normal. The secondary winding is floating. What voltage do you see
across the aux terminals (DC)?

Is a) above with the transformer connected to the alarm board?

Get a fuse in line with the secondary to save the transformer in case
something is shorted. You don't want to damage the new transformer. I would
use a fuse equal to the secondary current rating marked on the transformer.

On Tue, 26 Nov 2013 23:01:57 -0500, tm wrote:

That's normal. The secondary winding is floating.

Whew! I had expected a center-tapped transformer or something.

Thanks for setting my mind at ease on the odd voltages to the
ground lead.

The 20Volts I measured is probably because the RMS voltage must
be the 16.5Volts, so *that* part at least makes sense.

What voltage do you see across the aux terminals (DC)
with the transformer connected to the alarm board?

I measured 13.61 volts across the DC terminals with the AC
transformer in place.

That seems good, to me, if a bit low for charging a 12V battery.
http://farm8.staticflickr.com/7440/1...deb1394f_o.gif

Get a fuse in line with the secondary to save the transformer
in case something is shorted.

The transformer has a PTC fuse in the secondary.
But, I *do* agree with you.
I'm shocked there is no fuse.

I even asked at the intrusion alarm houses I visited today.
They said the board itself is protected from overloads, so,
nobody bothers with a fuse.

This reminds me of the situation with garage door torsion
springs where the "industry" puts in the cheapest spring
saving *them* ten bucks, but if you put in your own spring,
you *always* opt for the better (longer life) spring!

For me, I agree with you. I'm heading off to RadioShack
or Frys to get an inline fuse holder.

You don't want to damage the new transformer. I would
use a fuse equal to the secondary current rating marked
on the transformer.

It's a 16.5VAC (RMS) output, with a power of 45VA, so,
given I=P/V, I get I=45/16.5, where I is 2.7 Amps.

So, how does double that sound for a fuse, e.g.,
roughly around 5 Amps for the inline fuse for the
transformer secondary?

"Danny D'Amico" wrote in message
news
On Tue, 26 Nov 2013 23:01:57 -0500, tm wrote:

That's normal. The secondary winding is floating.

Whew! I had expected a center-tapped transformer or something.

Thanks for setting my mind at ease on the odd voltages to the
ground lead.

The 20Volts I measured is probably because the RMS voltage must
be the 16.5Volts, so *that* part at least makes sense.

What voltage do you see across the aux terminals (DC)
with the transformer connected to the alarm board?

I measured 13.61 volts across the DC terminals with the AC
transformer in place.

That seems good, to me, if a bit low for charging a 12V battery.
http://farm8.staticflickr.com/7440/1...deb1394f_o.gif

Get a fuse in line with the secondary to save the transformer
in case something is shorted.

The transformer has a PTC fuse in the secondary.
But, I *do* agree with you.
I'm shocked there is no fuse.

I even asked at the intrusion alarm houses I visited today.
They said the board itself is protected from overloads, so,
nobody bothers with a fuse.

This reminds me of the situation with garage door torsion
springs where the "industry" puts in the cheapest spring
saving *them* ten bucks, but if you put in your own spring,
you *always* opt for the better (longer life) spring!

For me, I agree with you. I'm heading off to RadioShack
or Frys to get an inline fuse holder.

You don't want to damage the new transformer. I would
use a fuse equal to the secondary current rating marked
on the transformer.

It's a 16.5VAC (RMS) output, with a power of 45VA, so,
given I=P/V, I get I=45/16.5, where I is 2.7 Amps.

So, how does double that sound for a fuse, e.g.,
roughly around 5 Amps for the inline fuse for the
transformer secondary?


You will measure 16.5 volts RMS AC when the load is 45 VA.

Use a 3 amp fuse.

Can you check the current draw with your meter on AC Amps? Just for
reference.

On Wed, 27 Nov 2013 01:49:57 -0500, tm wrote:

You will measure 16.5 volts RMS AC when the load is 45 VA.

Ah. I see. Makes sense. The voltage drops under load.

Use a 3 amp fuse.

Again, makes sense. That (roughly) equals the rating.

Can you check the current draw with your meter on AC Amps?

I measured roughly 700Ma to 800Ma AC current out of the secondary
winding when I powered it up and set the alarm and opened a door,
etc.

http://farm6.staticflickr.com/5542/1...b7dbacb0_o.gif
http://farm6.staticflickr.com/5493/1...483d2de9_o.gif
http://farm3.staticflickr.com/2865/1...43a084a9_o.gif

On Wed, 27 Nov 2013 03:48:00 +0000 (UTC), Danny D'Amico
wrote:

On Tue, 26 Nov 2013 01:33:21 -0500, tm wrote:

If someone mixed up that wiring, it could present a short circuit
to the power supply and battery.

The alarm has been working for years, so, I'm pretty sure the wires
didn't all of a sudden get changed.

The good news is that the new transformer arrived today.

However, the voltage output wasn't at all what I had expected from a
16.5VAC transformer secondary.
http://farm6.staticflickr.com/5532/1...7612e531_o.gif

I measured:
a) 20 VAC across the secondary

Reasonable. You tested it with no load, right?

b) 3.54 VAC across on side of the secondary to ground
c) 0.98VAC across the other side of the secondary to ground

Huh?

The secondary is isolated from the primary. Any measurements made
across the isolation are meaningless.

On Wed, 27 Nov 2013 14:03:09 -0500, krw wrote:

I measured:
a) 20 VAC across the secondary

Reasonable. You tested it with no load, right?

Correct.

Also, when plugged into the alarm system, it only drew 800mA.

b) 3.54 VAC across on side of the secondary to ground
c) 0.98VAC across the other side of the secondary to ground

The secondary is isolated from the primary. Any measurements made
across the isolation are meaningless.

Thanks.